1. Field of the invention
The present invention relates to a device to stimulate the human body with a vibration or a prescribed frequency.
2. Description of the prior art
Japanese Patent Laid-Open No. 209,355/83 discloses a vibrostimulative device wherein a vibratory plate to be placed on the human body is coupled through a closed gas space with a loudspeaker, while its voice coil is connected with a variable oscillator through an amplifier. The device has the advantages that its vibration frequency can be conveniently set to the most effective level for the subject; and that the gas used as the vibration-transmitting media transmits the vibration over a relatively large body area of the subject.
The device, however, has the drawback that, when the closed gas space is extended with a flexible hose having a relatively small diameter, it requires a relatively high power to attain a prescribed sound pressure on the vibratory plate because gases are generally low in vibration transmittability. This unnecessarily enlarges both vibratory plate and amplifier to raise the production cost of the device.